Pressure casting molds



June 20, 1967 J. M. uYs

PRESSURE CASTING MOLDS Filed Maron 4, 1965 v 3 MII I I l 1 1 INVENTOR.JOHANNES M. UYS

ATTO/MEX FIG.

United States Patent O 3,326,272 PRESSURE CASTING MOLDS Johannes M. Uys,Youngstown, hio, assiguor to The Youngstown Sheet and Tube Company,Youngstown, Ghio, a corporation of Ohio Filed Mar. 4, 1965, Ser. No.437,140 7 Claims. (Cl. 164-323) ABSTRACT F THE DISCLOSURE In pressurecasting apparatus an inclined mold in which a movable block insertablethrough any one of several slots in the mold top permits modification ofthe effective volumetric capacity of that part of the mold cavitycommunicating with a sprue passage at the mold bottom through whichmolten metal is introduced into the cavity.

This invention relates to the pressure casting of metals and morespecifically ferrous ones to fonn slabs for further processing in themanufacture of sheets, plates and other shapes by successive rolling,drawing and other physical reducing operations, and is particularlydirected to means for conserving the metal remaining in the ladle wheninsufficient in amount to form a slab of standard size after one or aplurality of such slabs have been cast.

For maximum efficiency reduction of slabs to sheets or other shapescontemplates that the slabs successively rolled or to be rolled in aspecified roll stand be of substantially uniform width and thicknessalthough variations in length in the direction of rolling are acceptableand cause no appreciable impairment in the effectiveness of theoperation, and it has been the practice in producing the slabs bypressure casting to fill successively a plurality of substantiallyidentical molds from a single charge of molten metal in a ladle. Thisfrequently results after a series of molds have been filled in leavingin the ladle of quantity of molten metal insuflicient to fill anothersuch mold and hence if teemed into one there is produced a slab ofnon-standard and non-uniform width requiring special treatment in therolling mill or, as is more usual, consignment to scrap of an undulylarge weight of metal either from the ladle or after it has cooled inthe mold.

It is therefore a principal object of this invention to provide forcombination and association with pressure casting apparatus means, moreparticularly a mold, in which slabs of standard width and thickness butof nonstandard and variant length may be cast whereby a quantity ofmolten metal in a ladle insufficient for producing a slab of standarddimensions may be used for casting one shorter than standard butotherwise substantially conforming to the requirements of the rollingmill or other apparatus in which it is to be further processed.

A further object is to provide a mold suitable for pressure casting thecavity of which is adjustable as to length and consequent volume withoutvarying those dimensions of the cavity which determine the width andthickness of a slab cast therein, with the result that the volume of themold cavity can be correlated in advance to the quantity of residualmetal in the ladle, if any, following the filling of a plurality ofstandard molds to thereby enable production from that metal of a finalslab of standard width and thickness but less than standard length.

A still further object is the attainment of these and other objects bythe provision of relatively simple means readily adaptable to existingpressure casting molds and which may conveniently be brought into playto form a slab of reduced length after the major portion of the metalinitially in the ladle has been exhausted.

Other objects, purposes and advantages of the invention ice willhereinafter more fully appear or Iwill be understood from the followingdescription of a preferred embodiment of it illustrated in theaccompanying drawing in which:

FIG. 1 is a diagrammatic vertical section of pressure casting apparatusof known character with which there is shown associated and combined atypical mold constructed in accordance with the invention and disposedin metal-receiving relation to other components of the apparatus;

FIG. 2 is a somewhat enlarged fragmentary detail of one portion of themold top and sides;

FIG. 3 is a corresponding fragmentary detail showing the rear end of themold blocked off and excluded from access by the metal introduced intothe mold near its front or lower end, and

FIG. 4 is a diagrammatic vertical section in the plane of the inner faceof the side wall nearest the observer of a modified embodiment of theinvention in which supplemental means for stabilizing the back block areprovided.

Referring now more particularly to the drawing the pressure castingapparatus diagrammatically illustrated therein which is typical withinknown practices will first be briey described as the disclosure of thedetails of its modification in accordance with the invention willthereby be rendered more readily susceptible to comprehension by thoseskilled in the art. Thus said apparatus comprises a refractory linedsteel ladle 1 preferably mounted on a suitable truck 2, comprisingwheels 2', supporting a receptacle 3 in which the ladle is received formovement rectilinearly along rails 4. A removable canopy or hood 5cooperative with the receptacle encloses the ladle and with it defines asealable chamber into which air under pressure may be admitted from amanifold 6 through a separable -connecting conduit 7 adapted to carryair for example at about 55 p.s.i. from the manifold and pasta controlvalve 8 to the interior of the chamber. Jacks 10 of usual constructionare provided for raising and lowering receptable 3 and its burdenrelatively to truck 2 and the usual means such as a scale (not shown)associated therewith enable the operator to determine by observation theweight of molten metal in the ladle at any time and in turn whethersufficient metal remains after a plurality of molds and have been filledto cast another full sized slab or only enough to cast one of less thannormal weight.

These are other variations of pressure casting possible such as wherethe molds are mounted on a mold carriage and the ladle and pressurevessel are stationary. In this case the ladle and pressure vessel can bejacked up to make contact with the mold or the front part of the moldcan be `lowered to make the contact.

Further in accordance with customary practice hood 5 is equipped with arefractory lined depending standpipe 12 which when in operative positionextends from the top of the hood into ladle 1 just short of its bottomto provide a Siphon tube into which the molten metal may be forced forejection from the standpipe when the upper end of the latter isconnected with a fitting 13 depending from the proximate end of asuperjacent mold 14, a gate 13 in the fitting permitting the passagethrough the latter to be closed after the mold has been filled. Fitting13 here shown in association with the mold 14 embodying the inventionmay be substantially identical with those customarily utilized withpressure casting molds as is the superjacent riser 15 in the top of the-mold and the several components of the latter are of course removablysecured together in the usual or other convenient way to enable theirseparation sufficiently to permit removal of the solidified metal massor slab after it has cooled.

Similarly to pressure casting molds of generally like charactercurrently yin use mold 14 comprises a bottom 16 preferably disposed atan angle to the horizontal such that it slopes toward the tracks atapproximately 3, parallel side walls 1718 normal to the bottom, a top 19parallel thereto, a stationary back block 20, including the customaryporous vent block 21, and a front wall 22, all of recti- -linear formand together defining a generally rectilinear moldcavity 23. Inaccordance with my invention, however, the top is provided with a seriesof slots 24 spaced longitudinally from each other, preferablyrectangular in shape and extending entirely across the top from one sidewall to the other, through any of which a movable back block 25,desirably having at its upper end a vent block 26 substantially similarto vent block 21 in the back wall of the mold, can be entered and pusheddown till it engages the mold bottom, thereby to adjust at the will ofthe operator the size of the mold cavity connected with fitting 13 to acapacity only slightly less than the amount of metal remaining in theladle after the bulk of it initially present therein has been expendedin filling one or more molds of normal capacity. Flanged graphite plugs30 desirably carrying bails 31 may be utilized t-o close those of theslots between the front end of the mold and that through which themovable back block 25 is entered while as illustrated in FIG; 4 ifadditional support for the back block to insure against its canting inthe mold under pressure of molten metal against its fr-ont face -is`deemed advisable angles 35, 36 or other appropriate means secured to themold top may be disposed against its opposite sides projecting above thetop.

Reference will now be had to the normal casting cycle in a pressurecasting unit comprising a ladle, say, of to 300 tons capacity withassociated hood, carriage, air pres- Vsure applying means and the like:After the ladle has received a charge of molten -metal and the hoodreplaced and sealed, truck 2 is moved along the tracks till aligned withone, usually the first, of a series of ordinary pressure casting moldsand the siphon tube 12 is connected to fitting 13 -thereof with gate 13open. Air pressure is next applied t-o the interior lof the hood,forcing molten metal from the bottom of the ladle into the superjacentmold until it rises in riser 15 far enough to compensate for theangularity of the top and bottom of the latter which meanwhile is beingvented through vent block 21 in its back block. After a sufficientamount of metal has been poured :gate 13 in fitting 13 is actuated toclose the sprue passage and the air pressure in the hood is thenrelieved as by actuation of a pressure relief valve (not shown) toenable the ladle to be lowered and moved to another, generally the next,mold in the series disposed at intervals along the tracks. Such molds ifintended for casting ferrous slabs are customarily from 102\6' long,20"-100" high, measured normal to the mold bottom, 3-15 wide between theside walls, and thus hold from about 1 to about 65 tons of metal whenfully charged. It is but seldom, however, u'nder practical conditions ofoperation, that the ladle is initially charged with substantiallyexactly the right amount of metal to fill a given series of molds, withthe result that it contains either more than sufficient to completelyfill the entire series or only enough to cornpletely fill all but thelast thereof; in either case a certain amount of residual metal is leftin the ladle after the maximum number of molds have been poured full.Hence, if conveniently, the last mol-d in the series is constructed inaccordance with my invention, the operator after filling of all theother molds can determine by observation of the lusual scale showing theweight of metal in the lad-le that there remains in the latter aninsufficient quantity to fill another standard mold and he then adjuststhe improved mold, by appropriate disposition of movable back block 25,to decrease the volumetric capacity of the cavity between it and thefront wall to accord substantially with the amount of residual metal inthe ladle so that when it is introduced into the shortened cavity itwill substantially fill it with resultant production of a slab save inrespect to length having the same dimensions as one cast in any othermold in the series.

It will now be appreciated it is not contemplated that in connectionwith each pressure casting unit a plurality of molds constructed inaccordance with rny invention will ordinarily be provided since itusually is suicient to have but one in each series of molds ofdimensions corresponding at least in all but length to the other moldstherein, although the individual molds may differ in length if desired,since the subsequent processing as noted is not seriously affected bylack of length uniformity in a given group of slabs as it is byvariations in one or both of their transverse dimensions.

While the foregoing discussion has been directed primarily to thecasting of ferrous metal slabs it is not to be inferred thereform myinvention may not be used advantageously in the pressure casting ofnon-ferrous metals and other materials while changes and modificationsin the form, structure, arrangement and relationship of the severalparts and components of my improved molds as herein described willreadily occur to those skilled in the art and may be made if desiredwithout departing from the spirit and scope of the invention as definedin the appended claims.

Having thus described my invention, I claim and desire to protect byLetters Patent of the United States:

1. In pressure casting apparatus comprising a track, a series of hollowmolds disposed at intervals along said track, a ladle adapted to containmolten metal movable on said track relatively to said molds fordisposition selectively into proximity to any of said molds and pressuremeans for transferring molten metal from the ladle to the cavity of themold in proximity thereto, that improvement which consists in providingin the top of a mold a series of slots communicating with the moldcavity, a back block insertable through any slot to prevent the passageof metal from one part of the cavity to the other, an-d means forclosing the slots communicating with that part of the mold cavity on themetal entering side of the block.

2. In pressure casting apparatus comprising a series of hollow moldsdisposed at intervals proximate to and inclining downwardly toward atrack, each providing a rectangular cavity defined by a bottom, side,back and front walls and a top, and means for transporting molten metallongitudinally of said track to the proximity of each mold and injectingit through an opening near the lower end of the mold cavity, thatimprovement which consists in the provision of a series of slots in thetop of a mold in the series at intervals between its front and backwalls, a removable -back block insertable through any of said slots todivide the mold cavity into two parts and prevent passage of metal fromthat part of the cavity proximate the lower end of the mold to that partproximate the back end thereof, thereby to define a metal receivingcavity of less capacity than the cavities yof other molds in the series,and removable means for closing the slots between that receiving saidblock and the front end of the mold.

3. In pressure casting apparatus comprising a track, a series of hollowmolds disposed at intervals proximate to and inclining downwardly towardthe track, each providing a rectangular cavity defined by a bottom,side, back and front walls and a top, means for transporting moltenmetal along said track to the proximity of each mold and injecting itthrough an opening near the lower end of the mold cavity, thatimprovement which consists in providing the top of a mold in the serieswith a plurality of transverse slots extending between its side walls, aremovable back block selectively insertable in any slot to therebydivide the mold cavity into a front and rear part each of less volumethan the unobstructed mold cavity, and removable means for closing theslots between said block when so inserted and the front end of the moldthereby to provide a substantially closed cavity for the reception ofmetal from the pressure injecting means to form a slab of less lengthbut of dimensions otherwise similar to slabs formed in the other moldsin the series.

4. In pressure casting apparatus comprising a mold including a top, sideand end walls and a bottom, a subjacent ladle adapted to receive moltenmetal and a severable conduit for conveying the metal upward from theladle to the mold, the mold top having a plurality of slots extendingtransversely between the side walls, a back block removably entered inone of the slots and adapted to confine molten metal within the moldbetween the block and one end wall, and means entered in the other slotsfor closing them to inhibit escape of molten metal from the mold throughsuch slots.

5. Apparatus as defined in claim 4 in which the removable back blockcomprises an air permeable portion disposed adjacent the mold top whensaid block is entered in any slot for emission of air from the moldcavity as molten metal enters thereinto.

6. Apparatus as defined in claim 4 in which each of said means enteredin said other slots comprises a anged block and a bail carried thereby.

7, In apparatus of the character described, a mold having a top andbottom with their upper and lower faces disposed in parallelism at anangle to the horizontal, a fitting adjacent its lower end defining asprue passage communicating with the interior of the mold, and a riseraixed to the top dening a substantially vertical passage likewisecommunicating therewith, front, side and back References Cited UNITEDSTATES PATENTS 416,706 12/1889 Aiken 249-158 443,785 12/1890 Nimmo76-112 684,773 10/1901 Anderson 249-158 X 888,133 5/1908 Welsh 249-1551,331,919 2/1920 Heiby et al 22-209 2,020,373 11/1935 Petzold 249-158 X2,154,234 4/1938 Eppensiner 249-158 X 3,032,841 5/1962 Sylvester 22-64 X3,222,735 12/1965 Sylvester 22-69 3,196,503 7/ 1965 Sylvester 22-69 I.SPENCER OVERHOLSER, Primary Examiner.

R. S. ANNEAR, Assistant Examiner.

1. IN PRESSURE CASTING APPARATUS COMPRISING A TRACK, A SERIES OF HOLLOWMOLDS DISPOSED AT INTERVALS ALONG SAID TRACK, A LADLE ADAPTED TO CONTAINMOLTEN METAL MOVABLE ON SAID TRACK RELATIVELY TO SAID MOLDS FORDISPOSITION SELECTIVELY INTO PROXIMITY TO ANY OF SAID MOLDS AND PRESSUREMEANS FOR TRANSFERRING MOLTEN METAL FROM THE LADLE TO THE CAVITY OF THEMOLD IN PROXIMITY THERETO, THAT IMPROVE MENT WHICH CONSISTS IN PROVIDINGIN THE TOP OF A MOLD A SERIES OF SLOTS COMMUNICATING WITH THE MOLDCAVITY, A BACK BLOCK INSERTABLE THROUGH ANY SLOT TO PREVENT THE PASSAGEOF METAL FROM ONE PART OF THE CAVITY TO THE OTHER, AND MEANS FOR CLOSINGTHE SLOTS COMMUNICATING WITH THAT PART OF THE MOLD CAVITY ON THE METALENTERING SIDE OF THE BLOCK.